Nonequivalent-F-induced relaxations in LaF3 single crystals over a broad temperature range
- 147 Downloads
The dielectric properties of LaF3 single crystals were investigated in the temperature range from 110 to 773 K and the frequency range from 100 Hz to 10 MHz. Two thermally activated relaxations (R1 and R2) and a dielectric anomaly (A) were observed. The lower temperature relaxation (R1) was ascribed to a polaronic relaxations due to fluorine ions diffusion within the F1 sublattice and fluorine ions hopping in F1 sublattice. The higher temperature relaxation (R2) is Maxwell–Wagner relaxation due to the blocking of electrodes associated with the ionic exchange between F1 and F2,3 sublattices and among the three nonequivalent sublattices. The anomaly appearing in the highest temperature range is related to the inductive effect arising from the coupled electron-ionic inductive response.
KeywordsLaF3 Dielectric Anomaly Delocalized Carrier Tysonite Structure Spectroscopic Plot
We thank financial support from the National Natural Science Foundation of China (Grant No. 11074001) and the Scientific Research Foundation for the Returned Overseas Chinese Scholars from the State Education Ministry. This work was supported in part by the open research fund of key laboratory of MEMS of Ministry of Education, Southeast University of China, and the Doctoral Startup Foundation of Anhui University (Grant No. 33190077).
- 1.Yusuke T, Kinichi M (2002) Hetero-epitaxial growth and optical properties of LaF3 on CaF2. Thin Solid Films 420–421:30–37Google Scholar
- 11.Privalov AF, Vieth HM, Murin IV (1994) Nuclear magnetic resonance study of superionic conductors with tysonite structure. J Phys 6(40):8237–8243Google Scholar
- 12.Privalov AF, Lips O, Fujara F (2002) Dynamic processes in the superionic conductor LaF3 at high temperatures as studied by spin-lattice relaxation dispersion. J Phys 14(17):4515–4525Google Scholar
- 14.Chadwick AV, Hope DS, Jaroszkiewicz G, Strange JH (1979) NMR and conductivity studies of ionic transport in LaF3. In: Vashishta P, Mundy JN, Shenoy GK (eds) Fast ion transport in solids. Elsevier, Amsterdam, pp 683–686Google Scholar
- 18.Frölich H (1958) Theory of dielectrics: dielectric constant and dielectric loss. Clarendon, Oxford, p 70Google Scholar